Variable speed transmission



` April l23, 1940.

o. E. szEKL-:LY VARIABLE SPEED TRANSMISSIN Filed Marchllg, 1937 4Sheets-Sheet 1 Quorum;

o. E. szEKELY VARIABLE SPEED TRANSMISSION April 23, 1940.

Filed March 19, 1937 4 Sheets-Sheet 2 o. E. szEKELY VARIABLE SPEEDTRANSMISSION Alsril 23, 1940.

A Filed March 19, 1957 4 sheets-sheet s April 23,- 1940. of@ szEKELY l2.198.397

y vmumam1 srEEn TRANSMISSION F1166 larh`19, 1937 4 Sheets-Sheet 4 'HuhnU0 aga Patented 1940 IPATENT OFFICE vAmAnLE SPEED TRANSMISSION otto E.surely, Elmira, N. Y., assignmto The merkkely Company, Inc., acorporation of New Application March-19,1937, serial No. 131,919 aclaims. `(ci. 'J4- 293) The present invention relates to improvements inmechanism for transferring power from a prime mover to a load, andincluding means for reversing the-direction of actuation of the load.

One of the features of the present invention is the provision of such amechanism for obtaining forward and backward movement of a load, andincluding means for controlling the torque and speed etfect's'deliveredvat the load, as well as the direction of actuation thereof. I Anotherfeature of the present invention is an assemblage of parts by which areverse gear comprises parts which are selectively controlled forproducing coupling between the structures connected to the prime moverand structures which are actuated under idling conditions at a speedVdetermined by the difference of the speeds of the prime mover and ofthe load: and which under other conditions comprises a connectionbetweenthe differentially actuatable member and a xed frame for producing amovement of the load in the opposite direction.

A further feature of the present invention is" an assemblage of partswhich is specifically advantageous for the coupling of a marine engineto a propeller, and comprises a differentiating gearing having two sungears and a planet pinion, with means for immobilizing the axis of theplanet pinion with respect to a fixed frame, or for controlling the rateof movement of such axis .with respect to the movement of one of the sungears, said one sun gear being connected to the prime mover and theother sun gear being connected for driving the load.

With these and other features in view as oli-4v jects of the invention,as will appear in the course of the following description and claims andas set out in the drawings, an illustrative form of construction isdisclosed by these drawings, in which:

Fig. 1 is an upright longitudinal sectional view .through atransmission.

Fig. 21s a transverse upright sectional view substantially on line 2-2of Fig. 1. l

Fig. 3 is a similar sectional view substantially on line-3 3 of Fig. 1.

Fig. 4 is a view corresponding to Fig. 1, but with Y certalnpartsthereof in elevation, and showing the employment of a reduction4 gear inthe driven nism space from a sump space I2. This central portion isillustrated also as having an annular portion I3 to provide bearings forthe -driven or tail shaft portions as will be described hereinafter. Thevopen frontor driving end of this 5 central structure III4 is closed bya member including the ange I4 which is bolted or other- Wise secured tothe central member- Ill, and has an inwardly extending annular structureI5, an annular channel I6 in this structure, a duet or 10 passage I1leading from the annular channel I6, and is further provided with a tubeI8 establish-v ing an inlet connection to the passage I1 and leading toa desired point of the sump I2. In

marine engine work, for example, it is not un- '15 l bevel gear 23,being splined or otherwise secured 25 to these gears 22 and 23. A stubend 20a of the driving shaft 20 is received by a roller bearing 24 in acentral hub 25 of a differential spider, as will be more closely dcribedhereinafter.

A revoluble differential cage is constituted by 30 a front end member 30which receives the bronze sleeves 2l and is supported from the housinmember I4 by anti-friction bearings 3|. This member has an annularchannel 32 in alignment with the channel I6, and from this channel 32the ports 33 'lead to the pump gears for deliverixg liquid thereto. Asecond member 34 has a flange located parallel to the member 30 .toprovide space for the pump gears, and also includes a structureextending around differentiating gearing members including the aforesaidsun gear 23, andI including a sleeve portion 34a which is supported byanti-friction bearings 35 relative to the annular portion I3 of thehousing structure I0. To assurelfreedom of movement of the parts, thesun gear 23 is mountedfor rotation relative to the differential casingstructure 34 by anti-friction bearings 36.

, The space between the parallel vfaces; `of the members 30, and 34` isoccupied (Fig. 2) by a ller structure and7 pump housing 40 whichhascavities for the reception of the inner pump gear 22 and mating pumpgear means, illustrated as the two pump pinions 4I. In the illustratedform, the pinions 4I are carried by bearings for rota- 55 tion aboutfixed bolts 42 which pass through the members 30, 34 and maintain theparts against separation under the liquid pressures which may bedeveloped during the operation of the system.

The assembly of structures 30, 40, 34 thus rotates together. Thechannels I6, 32 are constantly in open communication with one another,and are sealed against the escape of liquid therefrom, or the pentrationof air thereto, by the packings 45, 46.

The central spider portion U25 is formed with the pins which extendradially away from the axis ofthe driving shaft 20 and receive thedifferential pinions 5I which, on the one hand, are in mesh with thedriving sun lgear 23, and, on the other hand, are in mesh with the sungear 52 which is splined to the driven or tail shaft 53. The tail shaft53 has a stub end 53a which is supported by a bearing 24 within thespider 25,

to receive an actuating shaft 64 which has meansl such as the crank 65for rocking the same. This shaft 64 is supported by bearing members 66in the housing member I0. Within the housing, the shaft 64 has fixedthereto the actuator collars 61 which have beveled surfaces cooperativewith the surfaces 63. When the parts are in the position shown in Fig.3, the beveled surfaces permit the greatest separation of the two ears62, and hence the brake band isheld free of the cylindrical surface 60by the resiliency of its structure. When the crank 65 is moved, thebeveled surfaces 63 cooperate to force the ears 62 closer together 'andthus to apply the brake band 6I upon the cylindrical surface 60 and thusbring the differential case to a standstill relative to the frame.. v ,i

In the form shown in Fig. 1, the tail shaft 53 is provided with a heavyanti-friction bearing 10 close to the end of the housing structure, thisbearing being constructed and arranged to support both radial loads andend thrusts. The shaft 53 has a collar 53h for engagement with one endsurface of the axle race of the bearing 10, and the other end surfacethereof is engaged by the end of a sleeve 1I of a driving flangestructure 12, this structure being splined to the end of the tail shaft53 and being held in position by the washer 13 and nut 14 which engageson the outer threaded end of the shaft 53. Loads on the anti-frictionbearing 10 are transferred to the transmission by the engagement of theouter race of the bearing 10 with a shoulder 15 at one end, and byengagement with the clamping ring 16 .at the other end thereof.

For the purpose of determiningI and controlling the flow of uid in thepump, 4and the pressures to be developed thereby, the pump -housing 40is shown (Fig. 2) as having the discharge ports 40a. by which the fluidflows from the pumps back into the vspace of the generalhousing and thusto the sump I2. These passages 40a receive calibrated plugs 49 whichrestrict the flow of the fluid: and hence, when the passages and pumpare full of oil, the retardation on the movement of the oil sets up aback pressure at the pump which is suicient substantially to block thesame against relative movement of the gears 22, 4|.

For` the control of the fluid in the pump, the passage I1 is providedwith a rotatable closing member constituting an oil supply valve, andhaving an actuatable arm 8| which may be moved by the link 82 Ito closeoff the oil ilow more or less. Further, the channel I6, 32 communicatesby an air passage 63 with a conduit 84 which leads to a closing valve orcock 85. During the operation', the volume of flow of oil can becontrolled by movement of the valve 80, so that when the valve 80 isfully open, a maximum back pressure effect occurs by reason of the plugs49: and when the valve 80 is fully closed, no further oil has accessfrom the sump I2 to the channel I6, 32 and thus into the pump. However,the pump is unable to expel all of this oil and hence a partial backpressure or dragging action still occurs therein. It is also possible toregulate the rate of oil flow by a partial breaking of the vacuumcreated in the channel I6, 32 by pump action, through a slight openingof the air valve 85. Furthermore, when the control rate is determined,as is preferred, by theoil valve 80 (due to the greater sensitivity), itis possible to shift the system quickly from a condition of full driveand maximum torque, to the idling position in which the Lpump parts havesubstantially no dragging effect, by quickly opening the air valve 85 sothat on the one hand the suction of oil from the crank case I2 isstopped, a'nd on the other hand, the entering air serves to scavenge andclear the pump of oil.

The operation'of this structure is as follows:

When the device is used for driving a boat, and the prime mover and boatare at a standstill, all parts of the mechanism are likewise to beassumed without motion relative to the housing l0, I4. The sump I2contains a quantity ofliquid, such. as a low-freezing oil, and theoutlet valve 80 is closed'so that the pump parts can turn freely, andthe brake band 6I is free of the surface 60.

The prime mover can now be started in an appropriate way, so that theshaft 20 is driven. If it be assumed that the shaft 20 is being turnedat a speed of 1000 R. P. M., then the inner pump gear 22 and the sungear 23 are also being turned at this same rate. Since there is no backpressure at the pump and no retardationby brake band 6I upon thedifferential case 34, the inner pump gear 22 merely spins the pumppinions 4I. The bevel sun gear 23 turns the differential pinions 5Iabout their pins 50. Since the tail shaft 53 is at a standstill, thepinions 5I roll along the sun gear 52 and thus carry their axis pins 50and thus rotate the differential case 34 and the pump housing structure40. The rotation is governed by the ratio of the parts, and in theillustrated example, the differential case 34 will bev I turned in thesame direction as the driving shaft 20 but at a speed of 500 R. P. M.Thus, the inner pump gear 22 is turning at 1000 R. P. M while the pumphousing is turning in the same direction but at a speed of 500 R. P. M.

To obtain forward motion of the vessel, the oil valve 80 is moved towardopen-position. 4The oil is drawn in from the tube I8 into the pump andthen discharged therefrom with retardation by the plugs 4 9, is nowplaced under pressure :and a back pressure is established in the pumpwhich appears as a force acting upon the pump housing and upon thedifferential case to accelerate it in the direction of rotation of thedriving shaft 20. This is accompanied by a pressure at the pins upon thepinions 5l which seeks to cause the pinions to move faster bodily aboutthe axis of the drive shaft 20. Since the speed ofrotatlon of the sungear 23 is fixed by the prime mover speed, this pressure operates tocause a rotation of the sun gear 52 and therewith of the tail shaft 53,so that the tail shaft is now brought into motion at a speed determinedby the back pressure created by the valve 80, and ,by the loaddemandvupon the tail shaft 53. Thus, for a given and constant load onthe tail shaft 53, the successively greater obstruction and pressurescreatedin gradually opening the valve speed of 200 R. P. M. Thus, whenthe valve 80,

is fully `opened. and a hydraulic block exists at the pump,the pumphousing 40 is turning at the same speed as the inner pump gear 22, thatis, it is turning at the speed of the drivingv shaft 20; At this time,also, the pins 50 with the pinions 5| are being carried bodily aroundthe common axis of shafts 20, 53, at this same speed: and the 'gear 52is likewise being driven at this speed. Hence, the ratio of drive is 1:1or direct, between the shafts 20' and 53.` It will be noted that thisratio can not be exceeded, as the blocking action involves a matter yofback pressure created by the pump itself, and that the parts 4of thepump Vcannot overrun one another in this particular form of structure,by reason of power being introduced from' the driving shaft 20.

Ii the load demand on the tail shaft 53 should increase, then the torquedemand at the tail shaft 53 and sun gear 52 increases in similar ratio,and this increase will result in a rotation of pinions 5I about theirpins 50. The rotation of the pinions 5i about their axes is accompaniedby a relative movement of the differential case 34 and the pump housing4I) with respect to the driving shaft 20 and the inner `pump gear 22,since the back pressure effect formerly existing is no longer sufficientto maintain the parts at/ the particular relative speeds of the drivingshaft 20 and driven shaft 53 which has been existing. Hence, the tailshaft 53 passes to a lower speed.

It is obvious that either in direct drive or at the intermediate speedsdetermined by the hydraulic control constituted by the pump and valve,any changev in the speed and/or torque delivered to the driving shaft 20will be accompanied by changes in the speed and/or torque at the load.Thus, for a given and constant engine speed, at a torque which isprecisely satisfying the load demand for torque at a low relative speedof the load, an increase of the torque output at this constant 'speed ofthe prime mover will occasion an increase in the speed of the ta'ilshaft and thus of the load until the product of speed and torque at theload is again commensurate with the product of speed and torque band tothe cylindrical surface B0. This results' at the driving shaft.

If'it is desired to operate the tail shaft in a reverse direction, fromthe aforesaid idling position, the crank 35 is actuated to apply thebrake operate as simple reversing idlers and produce a rotation of thesungear 52 in an angular direction opposite to thatof the sun-gear 23and. at the same speed and substantially the same torque, so that theload is now driven in the opposite direction.

The particular construction lends itself also to the employment of areduction gear for linstances in which the speed of the prime mover isgreater than that required at the` load. In marine work, for example, anexcessive speed'of a propeller |00, connected to the tailV shaft 53,would result in `cavitation and loss of efficiency during theaccelerating and decelerating periods of the vessel.

From Fig. 4, it will be noted that the end ring 13 may be replaced by aringlGa for supporting an anti-friction bearing 10a which is intendedprimarily for resisting any tendency of whipping at the tail shaft 53.This tail shaft 53 is splined to a gear 12a of small diameter, which issupported against distortion by radial loads thereon, by the aforesaidanti-friction bearing 10a.

A rearhousing section H0 is connected to the central housing section I0,with the intermediate ring structure 16a clamped therebetween. This rearhousing structure lill supports the roller bearings 10x and holds themagainst permitting I endwise or axial movement in the nal driven shaft,substantially as described for the strong anti-friction bearing 10 inthe form of Fig. 1. Since the reduction of speed represents also anincrease in torque and hence of probable thrust effects, it is desirablein this form to provide amply strong bearings 10m.

These bearings lila: support the sleeve lla: of the coupling flange 12mwhich is connected for driving the propeller, in this specific example,and also support the sleeve IH of an internally cut gear H2 which is inmesh with the small gear 12a. Differences in the diameters of the gears12a, I I2 are provided for by the 'eccentric mount- 1 ings of their`respective shafts `53, H3. The structures 16a, lill, provide an oilsump, which may be separate from the general oil sump i 2,

and receives a supply of lubricant which is being constantly lifted bythe gear H2 in its movement and thus delivered to the various bearingsurfaces. l

'I'he final driven shaft H3 is illustrated as splined to the sleevesliz, III. and as` having a collar |I3a at its inner end and operating atits threaded outer end with a nut Ill to assure proper transfer ofthrust effects to the bearings. The rear end of the housing Ill) isclosedby a ring H5 havingan oil seal H5 therein.

It is obvious that the invention is not nlimited solely to theconstruction shown. but that it Vmay be employed in many ways within thescope of the appended claims.

1. A reverse and control gear mechanism cornprising a housing. a drivingshaft, a driven shaft;

a differentiating gearing including a diiferential case, a bevel sungear driven by the driving shaft, a bevel sun gear connected to thedriven shaft, and bevel planet pinion means journalled on the case forrotation about` the axes of the sun gears; a gear pump including a partconnected to the driving shaft and a part connected to the differentialcase, said parts comprising an inner gear, a `pump pinion meshingtherewith, and a pump housing having thereon an axis for said Apumppinion, said gear pump being effective upon rela- 75 tive movement todisplace iluid, -a sump for liquid and a conduit from said sump to saidgear pump, at least a part of said conduit being stationary with thehousing, and means for controlling the pressure of' uid at said partsand eil'ective through such pressure for causing said differential caseto rotate in the direction of the driving shaft, said fluid-controllingmeans including a valve onsaid stationary part of the conduit; and meansconnected to the housing for holding the differential case againstrotation.

2. A variable speed transmission comprising a sump for liquid, a drivingshaft, a driven shaft; a differentiating gearing having bevel sun gearsconnected to said shafts, and bevel planet pinion means; a gear pumphaving an inner gear con- ,V nectedto the driving shaft and a pumphousing.

with pump pinions journaled therein, said housing being connected tosaid planet pinion means, a supply duct through which said pump sucksliquid from theA sump, means for retarding the escape of liquid from thepump, a valve for selectively obstructing said duct, and an air valvefor admitting air to said duct between said valve and pump to break thesuction.

3. A reverse andcontrol gear mechanism comprising a main housing, adriving shaft, a driven shaft, said shafts being coaxial, a revolublestructure concentric with said shafts, anti-friction bearings betweensaid case and shafts, bevel sun gears connected to said shafts andlocated inside said revoluble structure, bevel planet pinion meansjournalled in said revoluble structure in mesh with the sun gears, brakemeans for immobilizing the revoluble structure relative to the frame; agear pump including a pump gear connected tov said driving shaft, a pumphousing forming part of said revoluble structure, and a pump pinionjournalled in said housing; means for supplying liquid to said lgearpump including a duct having a part stationary with the housing, a valveon said stationary part of the duct, and means for controlling theliquid pressure prevailing at said pump gear and pump pinion.

4. A variable speed transmission comprising a main housing, adriving'shaft, a coaxial driven shaft; a member revoluble about thecommon axis of said shafts, an end ange, and pivot pin means extendingsubstantially radially from the said common axis; a pair of bevel sungears located inside said member, and bevel planet pinion meansjournalled on the pivot pin means and in mesh 4with the sun gears, onesaid sun gear being connected to the driving shaft and the other saidsun gear being connected to the driven shaft; a second member revolubleabout the common axis and having an end flange, a pump housing betweensaid flanges, means for clamping the flanges and housing together sothat the members revolve as one, an inner pump gear xed on said drivingshaft and located inl said pump housing, a pump pinion journalled in thehousing in mesh with said pump gear, said pump housing including adischarge outlet from the said pump gears, means in the outlet for.restricting the flow of liquid therethrough; said second member havinga suction duct through which liquid is sucked by the pump gears when thedriving shaft and housing are turning at different rates, said main.

housing having a duct communicating with said suction duct, and a valvefor limiting the ow of I liquid through said ducts.

6. A variable speed transmission comprising a main housing, a drivingshaft, a coaxial driven shaft; a member revoluble about the common axisof said shafts and having an external braking surface, an end flange,pivot pin means extending substantially radially from the saidcommon-axis, and a brake band for engaging said braking surface andholding the member against rotation; a pair of bevel sun gears locatedinside said member, and bevel planet pinion means journalled on thepivot pin means and in mesh With the sun gears, one said sun gear beingconnected to the driving shaft and the other said sun gear beingconnected to the driven shaft; a second memberv revoluble about thecommon axis and having an end ange, a pump housing between said flanges,means for clamping ,the flanges andhousing together so that the membersrevolve as one, kan inner pump gear fixed on said driving shaft andlocated in said pump housing, a pump pinion journalled in the housing inmesh with said pump gear, said pump housing including a discharge outletfrom the said pump gears, means in the outlet for restricting the flowof liquid therethrough; said second member having a suction duct throughwhich liquid is sucked by the pump gears when the driving shaft andhousing are turning at different rates, said main housing having aduct/communicating with said suction duct, and a valve for limiting theflow of liquid through said ducts.

7. vA reverse and control gear mechanism comprising a housing, a drivingshaft, a driven shaft; a differentiating gearing including adifferential case, a bevel sun gear driven by the driving shaft, a bevelsun gear connectedv to the driven shaft, and bevel planet pinion meansjournalled on the case for rotation about the axes of the sun gears; agear pump including a part connected to the driving shaft and a pa-rtconnected to the Ydifferential case,. said parts .comprising an innergear, a pump pinion meshing therewith, and a pump housing having thereonan axis'for said pump pinion, said gear pump being effective uponrelative movement to displace fluid, a sump for liquid and a conduitfrom said sump to said gear pump, at least a part ofsaid conduitbeingstationary with the housing, and means for controlling the pressureof fluid atsaid parts and effective through such pressure for causingsaid differential case to rotate inthe d-irection of the driving shaft,said fluid-controlling means including a valve on said stationary vpartof the conduit and `also including a valve air bleeder opening into saidduct to permit air to be drawn into said gear pump; and means connectedto the housing for holding the differential case against rotation.

8. A variable speed transmission comprising a housing including asumpfor liquid, a driving shaft, a driven shaft; a differentiating gearinghaving bevel sun gears connected to said'shafts, and bevel planet pinionmeans; a gear pump having an inner gear connected to the driving shaftand a pump housing with pump pinions journaled therein, said housingbeing connected to said planet pinion means, a supply duct through whichsaid pump sucks liquid from the sump,

at least a part of the supply duct being stationary With the housing,means for retarding the escape of liquid from the pump, a valve on thehousing for selectively obstructing said stationary part of the duct,and an air valve stationaryl with the housing for admitting air to saidduct 75 between said valve and pump to break the suction.

9. A variable speed transmission comprising a main housing, a drivingshaft, a coaxial driven shaft; a member revoluble about the common axisof said shafts, an end ilange, and pivot pin means extendingsubstantially radially from the said common axis; 'a pair of bevel sungears 1ocated inside said member, and bevel planet pinion means journalled on the pivot pin means and in mesh with the sun gears, onesaid sun gear` being connected to the driving shaft and the other saidsun gear being connected tothe driven shaft; a second member revolubleabout the common axis and having an end flange, a pump housing betweensaid flanges, means for clamping the flanges and housing together sothat the members revolve as one, an inner pump gear xed on' said drivingshaft and locatedin said pump housing, a pump pinion journalled in thehousing in mesh with said pump gear, said pump housing including adischarge outlet from the said pump gears, means in the outlet forrestricting the flow of liquid therethrough; said second member having asuction duct through which liquid is sucked by the pump gears when thedriving shaft and housing are turning at diierent rates, said mainhousing having a duct communicating with said suction duct, a valve forlimiting the flow of liquid around the pump gears through said suctionduct, and an air bleeder valve for admitting air into said suction ductbetween said rst valve and the pump gears.

, OTTO E. SZEKELY.

